1. Field of the Invention
The present invention relates generally to the field of bookbinding and, in particular, to a method of applying a wrap sheet to the spine of a book hardcover and related guide apparatus.
2. Description of Related Art
It is now possible to print and bind a book using relatively low cost desktop equipment. Such books can approach the quality and appearance of mass-produced bound books, including hardcover books. One such prior art technique uses a binder strip having an adhesive surface, such as disclosed in U.S. Pat. No. 4,496,617. The binder strip is typically applied to a stack of sheets to be bound using a desktop binding machine such as disclosed in U.S. Pat. No. 5,052,873. The binding machine carries out the binding operation by suitably positioning the binder strip relative to the stack to be bound and applying heat and pressure so that the edges of the stack are bound. Next, a hardcover assembly can be applied to the bound stack to provide the finished book. One such typical prior art binding sequence is described below.
Referring now to the drawings, FIG. 1 shows a stack of sheets 15 to be bound. A first folded liner sheet 12, forming sheets 12A and 12B the same size as the sheets to be bound, is positioned on the top of the stack 15 and a second folded liner sheet 14, forming sheets 14A and 14B, is positioned on the bottom of the stack. The liner sheets 12 and 14 are preferably of a relatively heavy stock as compared to the sheets 15 to be bound. Once the liner sheets 12, 14 and stack of sheets 15 have been assembled, the combined stack 10 is bound together using a conventional binder strip 16 as described in U.S. Pat. No. 4,496,617, the contents of which are hereby fully incorporated by reference into the present application. The actual binding is preferably is carried out using a desktop binding machine as described in U.S. Pat. No. 5,052,873, the contents of which are hereby fully incorporated by reference into the present application. The bound stack 10 is shown in FIG. 2, with the adhesive present in the binder strip 16 operating to bind the individual sheets together and to the paper substrate of the binder strip 16.
FIG. 3 shows details of a typical prior art hardcover assembly 18 that is applied to the bound stack 10 of FIG. 2. Usually, the cover assembly 18 is completely assembled and sold separately to the user. As will be described, the cover assembly 18 will be manufactured in various sizes to accommodate differing size stacks 10 in terms of stack thickness and to accommodate different formats such as 8½ by 11 inch formats. A user can request that certain information be preprinted on the assembly 18, including title information and any other graphics. As will be described later, the present invention provides an attractive alternative to preprinting the title information.
The typical hardcover assembly 18 includes the front and back cover sections halves 18A and 18B, respectively, separated by a spine section 18C. The cover assembly includes a pair of relatively stiff cover boards 24A and 24B made of cardboard or the like. The cover boards 24A and 24B are typically 8⅜ inches by 11 5/16 inches for binding 8½ by 11 inch stack 10 and correspondingly smaller for an 8 ½ by 8½ stack. The cover boards are covered with a flexible cover membrane 22, typically fabric, which is folded around the edges of the cover boards, as depicted in FIG. 3. That part of the cover membrane 22 disposed intermediate the opposite edges 25A and 25B of the cover boards is unsupported and is thus relatively flexible. A length of fabric or stiff paper, typically 0.010 inches thick, is preferably disposed in the spine section 18C of the hardcover assembly 18 so as to slightly stiffen the membrane 22 in that location so that a desired shape is achieved when the bound book is opened and closed. The membrane regions 28A and 28B disposed between the respective edges of the spine section 26 and the respective edges 25A and 25B of the cover boards 24A and 24B are referred to as gutter regions. The gutter regions 28A and 28B are each fixed in width at ⅜ of an inch. The gutter regions define the flexible portion of the cover membrane. Alternatively, a spine board (not depicted), made of the same material as the cover boards 24A and 24B and having a shape that generally corresponds to the spine region 26, can be used. The spine board, which is typically 0.088 inches thick, functions to stiffen the spine 26, with spine flexibility being provided by the flexible gutter regions 28A and 28B disposed between the respective edges of the cover boards 24A and 24B and the respective edges of the spine board. When the spine board is used, the gutter region 28A and 28B widths are preferably increased slightly to 7/16 of an inch.
The spine region 26 width varies, along with the width of the spine board if one is used, depending upon the width of the stack 10 to be bound. The cover assemblies are preferably prefabricated in various widths to accommodate stacks 10 of various widths as set forth below in Table 1.
TABLE 1Spine 26 WidthStack ThicknessModel(inches)(inches)A ⅜To ¼B ½¼ to ½C ¾½ to ¾D1¾ to 1E1¼1 to 1¼F1½1¼ to 1½
The number of available spine widths can be increased or decreased from the values set forth above in Table 1, with a larger number increasing the difficulty of maintaining an adequate inventory and a smaller number detracting somewhat from the appearance of the final product in the spine region.
Referring back to FIG. 3, the cover assembly 18 is prefabricated using a pair of pressure sensitive adhesive sheets structure 30A and 30B. Further details of the adhesive sheets are also shown in FIGS. 4 and 5. Adhesive sheet structures 30A and 30B are dimensioned 8¼ by 10¾ inches when the stack 10 size is 8½ by 11 inches, to cover the interior periphery of the folded portions of the cover membrane 22A and 22B and to further secure the periphery of the membrane to the respective cover boards 24A and 24B. The smaller size of the underlying sheets 32A and 32B of the sheet structure ensures that the folded liner sheets 12A and 14A completely cover sheets 32A and 32B despite any small misalignment. Each sheet structure includes a respective bottom sheets 32A and 32B and an upper major release liner 36A and 36B. A layer of pressure sensitive adhesive 34A and 34B is disposed intermediate that upper liner and bottom sheet. A pressure sensitive adhesive manufactured by National Starch and Chemical Company and marketed under the designation Instant-Lok, type HL PSA 20-81, has been found suitable for this application. The adhesive layers 34A and 34B are preferably 0.003 to 0.004 inches in thickness.
The upper major release liners 36A and 36B are disposed over a majority of the underlying pressure sensitive adhesive layers. Generally, at least 75% of the adhesive layers are covered by the respective upper major release liners 36A and 36B, with a remaining strip of the adhesive along the inner edge of the sheet structures not being covered by the major release liners 36A and 36B. Instead, upper minor release liners 38A and 38B are disposed over the exposed adhesive strips. This relationship is shown schematically in FIG. 5 (not to scale) where a portion of the sheet structure 30B is depicted. As can be seen, the pressure sensitive adhesive layer 34B is disposed between the bottom sheet 32B and upper major and minor release liners 36B and 38B. That portion of the adhesive layer 34B not covered by the upper major release liner 36 is covered by a separate upper minor release liner 38B. The minor release liner 38B is actually positioned contacting the adhesive layer 34B and is secured in place by the adhesive layer. As is well known, all of the release liners 36A, 38A, 36B and 38B are fabricated from a material that only slightly adheres to the pressure sensitive adhesive so that the release liners can be manually separated from the adhesive without damage to the adhesive or the release liners. As part of the prefabrication of the hardcover assembly, conventional case glue 56 (not depicted in FIGS. 4 and 5) is applied to the top of the cover sections 18A and 18B and to the bottom sheets 32A and 32B. The sheet structures are then positioned over the respective cover sections 18A and 18B as shown in FIG. 3 so that the sheet structures will be secured to the cover sections by the case glue. Thus, the sheet structures 30A and 30B are secured to the cover boards 24A and 24B and to the peripheral portions of the cover membrane 22 by way of the case glue. This completes the prefabrication of the hardcover assembly 18.
Referring now to FIGS. 6 and 7, a prior art guide apparatus 40 is used for applying the hardcover assembly 18 to the bound stack. The guide apparatus includes a flat base member having a receiving surface 42 that is somewhat larger that the largest book to be bound when the book is in the open position. A stop member 44 having two orthogonal segments is supported on the upper surface 42 of the base member and extends around two adjacent sides of the base member. A ledge member 46, also having two orthogonal segments, is supported above the stop member 44 and, as can be in FIG. 7, have outer edges 46A which extend past the edge 44A of the stop member a small distance E, with the overhang being typically 0.14 inches. The height of the ledge member above the support surface is great enough to accommodate the thickness of the cover sections 18A and 18B of the cover assembly 18. The ledge member 46 extends along stop member 44 in one direction a distance Y (FIG. 6) that is somewhat smaller than the closed width of the smallest book to be bound. The distance Z, the distance that the ledge member 46 extends along stop member 44 in the other direction, is typically about twice dimension Y.
The guide apparatus 40 also includes two or more vertical stop members, such as 48A, 48B and 48C, with vertical stop member 48A being supported on ledge member 46 about one third of the distance Y of the ledge member from the corner formed by the intersection of the two ledge member 46 segments. Vertical stop member 48B and 48C are at approximate equal distances along the other ledge member 46 segment. As can best be seen in FIG. 7, the vertical stop members each have a planar surface, surface 50C for example, that coincides with the inner edge, edge 44A for example, of the stop member. This configuration also applies to the planar surfaces 50A and 50B of vertical stop members 48A and 48B.
The completion of the book binding sequence will now be described, starting with reference to FIG. 8A. The opened. hardcover assembly 18 is first positioned on the guide apparatus receiving surface 42, with the upper release liners 36A and 36B facing upwards. As indicated by arrow 52, the hardcover assembly is moved along the surface 42 of the guide apparatus until the edges of cover section 18B is positioned under the ledge member 46, abutting the inner edge 44A of the stop member 44, as shown in FIG. 7. Thus, the outer edge 46A of the ledge member 46 will be positioned a fixed distance E from the edge of cover 18B along the full length of both orthogonal segments of the ledge member 46. The outer edge 46A will provide a guide for positioning the bound stack 10, as will be described. Although not shown in FIGS. 8A–8M, the prior art guide apparatus preferably includes a manually activated clamp mechanism that grips the edge of the hardcover assembly 18 and assists in holding the assembly in place. Further, the prior art guide apparatus can include a book thickness measurement apparatus that includes opposing fixed and movable members which define a stack receiving region intermediate the two members. A user can position the stack vertically between the two members and then move the movable member inward toward the fixed member so the spacing between the two members corresponds to the thickness of the stack. A calibrated indicator connected to the movable member provides a reading indicating whether the thickness of the stack falls within the A, B, C, D, E or F category set forth in Table 1 above so that the proper width binder strip can be easily selected.
Once the hardcover assembly 18 is properly positioned on the guide apparatus 40, the user manually separates the upper minor release liner 38B as shown in FIG. 8B from the assembly 18. This will expose a relatively narrow strip of the underlying pressure sensitive adhesive 34B adjacent spine region 26. Next, the bound stack 10 is placed over the upper major release liner 36B, with the edges of the stack engaging edge 46A of the ledge member 46 along both orthogonal segments. FIG. 7 shows the edge of stack 10 engaging edge 46A along one of the two segments. As shown in FIG. 8C by arrows 52, that portion of stack 10 along the exposed adhesive 34B is not placed on the exposed adhesive until the orthogonal edges of the stack are positioned against edge 46A of both segments. Once the correct position is achieved, the stack is forced down upon the exposed pressure sensitive adhesive 34B as shown in FIG. 8D. This operates to secure the folded liner sheet 14A of stack 10 to cover section 18B of the hardcover assembly 18 in a correctly aligned position.
The next step is to secure the remainder of the folded liner sheet 14A of stack 10 to the adhesive 34B of assembly 18. Referring to FIG. 8E, the free edge of stack 10, including liner sheet 14A, is lifted up and rotated away from the upper major release liner 36B. This permits the release liner 36B to be separated from the hardcover assembly 18 thereby exposing the remainder of the pressure sensitive adhesive 34B. As shown in FIG. 8F, the spine portion of stack 10 held down against the hardcover assembly 18 with one hand while stack 10 is rotated over the adhesive 34B with the other hand. As shown in FIG. 8G, the user then presses the stack 10 down on the hardcover assembly 18. This causes the remainder of the liner sheet 14A of the stack to be secured by the remainder of adhesive 34B to cover section 18B of the hardcover assembly 18. The second cover section 18A of the hardcover assembly will now be attached.
Referring to FIG. 8H, the upper minor release liner 38A is next separated from the hardcover assembly 18 thereby exposing a strip of pressure sensitive adhesive 34A adjacent spine region 26. The user then lifts the cover section 18A of the hardcover assembly away from the surface 42 of the guide apparatus and rotates the cover 18A around the spine. As indicated by arrows 54 of FIG. 81, the cover section 18A is positioned so that the edges of the cover section 18A contact the planar surfaces 50A, 50B and 50C of the respective three vertical stop members 48A, 48B and 48C. This is shown in phantom in FIG. 7. The hardcover assembly 18 is then positioned correctly with respect to the bound stack 10. The user then forces the cover section 18A down as shown in FIG. 8J so that an edge of folded liner sheet 12A of stack 10 is secured to the hardcover assembly 18 by way of the exposed strip of adhesive 34A.
As shown in FIG. 8K, the user then lifts cover section 18A up and rotates the cover away from stack 10, with a narrow strip of liner sheet 12A of the stack remaining secured to cover section 18A. This permits upper major release liner 36A to be separated from hardcover assembly 18 thereby exposing the remainder of pressure sensitive adhesive layer 34A. Cover 18A is then rotated back down onto stack 10, where the edges of the cover should again be in contact with the surfaces 50A, 50B and 50C of the respective stops 48A, 48 and 48C as shown in FIG. 8L by arrows 58. The user then presses down on cover section 18A as shown in FIG. 8M thereby securing the cover section 18A to folded liner sheet 12A of stack 10. This completes the binding sequence. FIGS. 9A and 9B show the completed book in a closed position and FIG. 10 shows the book in an opened position, at the last page of the book, so that folded liner sheets 14A and 14B are depicted. Sheet 14A is secured to hardcover section 18B by way of adhesive 34B and sheet 12A at the front of the book is secured to hardcover section 18A by adhesive 34A. The region between the binder strip 16 and the spine region 18C is not attached so that, when the book is opened as shown in FIG. 10, the spine region does not attempt to fold with the binder strip 16. Thus, the book will lay flat when opened and will not tend to fold shut. Further, the spine region 18C will not distort when the book is opened to the same degree it would if the spine region 18C was attached. As previously noted, a fairly stiff fabric strip 29 is positioned in the spine region intermediate the gutter regions 28A and 28B (FIG. 3) so as to hold the shape of the spine region 26 when the book is opened and closed. Fold lines 27A and 27B are formed naturally in the membrane 22 in the regions near the edges 25A and 25B of the cover boards thereby further enhancing the appearance of the final product.
Although the final hardcover book is similar in appearance and quality to a commercial mass-produced book, it would be advantageous to be able to further enhance the appearance of such books using desk-top equipment. This and other advantages of the subject invention will become apparent to those skilled in the art upon a reading of the following Detailed Description of the Invention together with the drawings.